OF ARTS AND SCIENCES. 345 



guished from those of the (38 dibrompyromucic acid. The acid melts 

 sharply at 155-156°, and sublimes unaltered at a higher temperature. 

 The solubility of the acid in water at 19°. 5 was determined in the 

 usual manner. A weighed quantity of a solution of the acid saturated 

 at 19°. 5 was boiled with baric carbonate, and the barium dissolved 

 determined by precipitation with sulphuric acid : 



I. 42.8007 grm. solution saturated at 19°.5 gave 0.0724 grm. BaS0 4 . 

 II. 51.4109 grm. solution saturated at 19°.5 gave 0.0907 grm. BaS0 4 . 



According to these determinations, the solution saturated at 19°. 5 

 contained the following percentages of acid : 



I. II. 



0.26 0.27 



Baric (38 Dichlorpyromucate, Ba(C 5 HCl. 2 3 ) 2 . 4 H 2 0. — The barium 

 salt was prepared by precipitating a dilute solution of the ammonium 

 salt with baric chloride, and recrystallizing the product thus obtained 

 from water. The salt is sparingly soluble in hot water, still less solu- 

 ble in cold water, and crystallizes from a hot concentrated solution in 

 long irregular flat prisms which contain four molecules of water. 



The salt is permanent in the air, effloresces over sulphuric acid, and 

 loses its water readily at 100°. 



I. 1.4513 grm. air-dried salt lost at 100° 0.1795 grm. H 2 0. 



II. 0.4908 grm. air-dried salt gave 0.1981 grm. BaS0 4 . 



Calculated for Found. 



Ba(C 5 HCl 2 3 ) 2 .4H 2 0. I. II. 



H 2 12.66 12.37 



Ba 24.07 23.73 



0.4751 grm. salt dried at 100° gave 0.2205 grm. BaS0 4 . 



Calculated for 



Ba(C 5 HCl 2 3 )j. Found. 



Ba 27.56 27.29 



The solubility of the salt in water at 19.5° was determined in the 

 usual manner. 



I. 28.4671 grm. solution saturated at 19°.5 gave 0.0561 grm. BaS0 4 . 

 II. 28.6844 grm. solution saturated at 19°.5 gave 0.0573 grm.BaS0 4 . 



The solution saturated at 19°.5 therefore contained the following 

 percentages of anhydrous salt : 



I. ii. 



0.42 0.43 



